English
Related papers

Related papers: Adaptive Weighting in Radio Interferometric Imagin…

200 papers

Context. Most popular algorithms in use to remove the effects of a telescope's point spread function (PSF) in radio astronomy are variants of the CLEAN algorithm. Most of these algorithms model the sky brightness using the delta-function…

Instrumentation and Methods for Astrophysics · Physics 2017-12-18 L. Zhang , S. Bhatnagar , U. Rau , M. Zhang

The sky-averaged, or global, background of redshifted $21$ cm radiation is expected to be a rich source of information on cosmological reheating and reionizaton. However, measuring the signal is technically challenging: one must extract a…

Instrumentation and Methods for Astrophysics · Physics 2016-08-03 Tejaswi Venumadhav , Tzu-Ching Chang , Olivier Doré , Christopher M. Hirata

Envisioned for fifth generation (5G) systems, millimeter-wave (mmWave) communications are under very active research worldwide. Although pencil beams with accurate beamtracking may boost the throughput of mmWave systems, this poses great…

Networking and Internet Architecture · Computer Science 2019-08-29 Rafail Ismayilov , Megumi Kaneko , Takefumi Hiraguri , Kentaro Nishimori

The data reduction procedure for radio interferometers can be viewed as a combined calibration and imaging problem. We present an algorithm that unifies cross-calibration, self-calibration, and imaging. Being a Bayesian method, that…

Instrumentation and Methods for Astrophysics · Physics 2019-07-23 Philipp Arras , Philipp Frank , Reimar Leike , Rüdiger Westermann , Torsten Enßlin

Double-Fourier interferometry is the most viable path to sub-arcsecond spatial resolution for future astronomical instruments that will observe the universe at far-infrared wavelengths. The double transform spatio-spectral interferometry…

A high-sensitive interferometric scheme is presented. It is based on homodyne detection and squeezed vacuum phase properties. The resulting phase sensitivity scales as $\delta\phi \simeq {1/4} \bar{n}^{-1}$ with respect to input photons…

Quantum Physics · Physics 2009-10-28 Matteo G. A. Paris

We present in this paper an innovative data reduction method for single-mode interferometry. It has been specifically developed for the AMBER instrument, the three-beam combiner of the Very Large Telescope Interferometer, but can be derived…

Astrophysics · Physics 2009-11-11 E. Tatulli , the AMBER consortium

Context: Radio interferometers measure frequency components of the sky brightness, modulated by the gains of the individual radio antennas. Due to atmospheric turbulence and variations in the operational conditions of the antennas these…

Instrumentation and Methods for Astrophysics · Physics 2023-10-25 Jakob Roth , Philipp Arras , Martin Reinecke , Richard A. Perley , Rüdiger Westermann , Torsten A. Enßlin

The Fast Fourier Transform (FFT) is widely used in applications such as MRI, CT, and interferometry; however, because of its dependence on uniformly sampled data, it requires the use of gridding techniques for practical implementation. The…

Numerical Analysis · Mathematics 2025-12-22 Federico Achini , Paola Causin , Sara Vanini , Ke Chen , Simone Scacchi

The construction of Parseval fusion frames is highly desirable in a wide range of signal processing applications. In this paper, we study the problem of modifying the weights of a fusion frame in order to generate a Parseval fusion frame.…

Functional Analysis · Mathematics 2025-02-17 Ehsan Ameli , Ali Akbar Arefijamaal , Fahimeh Arabyani Neyshaburi

Due to its simultaneous deep imaging and integral field spectroscopic capability, an Imaging Fourier Transform Spectrograph (IFTS) is ideally suited to the Next Generation Space Telescope (NGST) mission, and offers opportunities for…

Astrophysics · Physics 2007-05-23 James R. Graham

A technique is described that is used to improve the detection of radio-frequency interference in astronomical radio observatories. It is applied on a two-dimensional interference mask after regular detection in the time-frequency domain…

Instrumentation and Methods for Astrophysics · Physics 2012-03-01 A. R. Offringa , J. J. van de Gronde , J. B. T. M. Roerdink

Phase shifting interferometric (PSI) techniques are among the most sensitive phase measurement methods. Owing to its high sensitivity, any minute phase change caused due to environmental instability results into, inaccurate phase…

To promote precision medicine, individualized treatment regimes (ITRs) are crucial for optimizing the expected clinical outcome based on patient-specific characteristics. However, existing ITR research has primarily focused on scenarios…

Methodology · Statistics 2024-02-20 Chang Wang , Lu Wang

Point Spread Function (PSF) modeling is a central part of any astronomy data analysis relying on measuring the shapes of objects. It is especially crucial for weak gravitational lensing, in order to beat down systematics and allow one to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Joel Bergé , Sedona Price , Adam Amara , Jason Rhodes

We propose a method to build an astronomical interferometer using continuous variable quantum teleportation to overcome the transmission loss between distant telescopes. The scheme relies on two-mode squeezed states shared by distant…

Quantum Physics · Physics 2025-09-03 Yunkai Wang , Yujie Zhang , Virginia O. Lorenz

There are several solutions to code the signal arising from optical long baseline multi-aperture interferometers. In this paper,we focus on the {\bf non homothetic spatial coding scheme} (multiaxial) with the fringe pattern coded along one…

Astrophysics · Physics 2009-11-11 E. Tatulli , J. -B. LeBouquin

Tomographic image reconstruction is relevant for many medical imaging modalities including X-ray, ultrasound (US) computed tomography (CT) and photoacoustics, for which the access to full angular range tomographic projections might be not…

Image and Video Processing · Electrical Eng. & Systems 2019-06-14 Valery Vishnevskiy , Richard Rau , Orcun Goksel

We demonstrate a novel mesh of interferometers for programmable optical processors. Employing an efficient programming scheme, the proposed architecture improves energy efficiency by 83% maintaining the same computation accuracy for weight…

Emerging Technologies · Computer Science 2022-11-18 Kaveh , Rahbardar Mojaver , Bokun Zhao , Odile Liboiron-Ladouceur

Radio interferometry is the current method of choice for deep space astronomy, but in the past few decades optical techniques have become increasingly common. This research seeks to characterize the performance of aperture masking…

Instrumentation and Methods for Astrophysics · Physics 2020-08-28 Kyle Morgenstein